The present disclosure relates to optical transceiver that is pluggable into a host device for optical communications.
Pluggable optical transceivers are widely used for data transmission in fiber optical communications. A pluggable optical transceiver can receive electric signals containing encoded data, convert the electric signals into optical signals, and transmit the optical signals through an optical data link. The pluggable optical transceiver can also receive optical signals containing encoded data, convert the optical signals into electric signals, and transmit the electric signals to a host device via an electrical interface. The electric interface and dimensions of pluggable optical transceivers can be defined by various device standards such as Small Form-factor Pluggable (SFP).
Referring to FIGS. 1A-1C, a host device 200 includes a chassis 210, and a circuit board 220 and a cage 230 mounted on the chassis 210. A conventional pluggable optical transceiver 100 is plugged into the cage 230. The cage 230 includes an electric interface (not shown) that is configured for transmitting data-carrying electric signals between the circuit board 220 and a remote device.
Referring to FIGS. 1A-4, a conventional pluggable optical transceiver 100 includes a lower housing member 110, an upper cover 120, and one or more interconnected electric circuit boards 130A and 130B. The lower housing member 110 includes an outer portion 115 and a lower portion 118. When the pluggable optical transceiver 100 is plugged into the cage 230, the outer portion 115 and, optionally, part of the lower portion 118, extend outside of the chassis 210.
The electric circuit boards 130A and 130B can be arranged in a stack and mounted to the lower housing member 110. The electric circuit boards 130A and 130B are can be enclosed by the upper cover 120 and the lower housing member 110 when the upper cover 120 is mounted on the lower housing member. When enclosed, an air gap exists between the upper cover 120 and the upper electric circuit board 130A. The electric circuit board 130B includes an electric interface 135 that is configured to communicate with the electric interface in the cage 230. The electric interface 135 and the electric interface in the cage 230 can be defined by a standard for pluggable optical transceivers such as Small Form-factor Pluggable (SFP) and Transceiver Multi-Source Agreement (MSA). An optical module 140 mounted to the electric circuit board 130B includes an optical interface 145 configured to be coupled to an optical fiber for receiving or transmitting optical signals to a remote device.
A major challenge for some conventional pluggable optical transceivers is associated with the heating generated by the electric circuits during operations. As increasing system functions are integrated into a pluggable transceiver module, more heat is generated by the electronic components on the circuit boards. Since during the operation a pluggable optical transceiver may be plugged into a cage without air circulation, temperature of the electric circuit board can be elevated to such high level to cause malfunction in the pluggable optical transceiver. There is therefore a need for a pluggable optical transceiver that can provide appropriate data communication functions without the above described overheating problems.